Mini Bison(Bison Brevis) To Modern Bison, click here To Fossil Bison, click here
Figure 1: Diagram of Mini Bison. Source from: Jackie Chan
The future animal, Bison Brevis, commonly known as the Mini Bison evolved from the American Bison 150 million years ago. The Latin name, Bison Brevis describes the size reduced compared to the American Bison. This Mini Bison is very different from the American Bison. The most significant difference is that the Mini Bison became omnivores; feeding on both vegetation and insects, as well as small mammals such as rabbits and rats. Their body size reduces from its previous sub species, but evolved into being more flexible and agile on land. This type of bison lost the shaggy fur due to the change of global climate, leaving only a thin layer of stubble below their neck and on their back. The Mini Bison also developed longer legs and reduced the body weight for better agility and reaction. Now the Mini Bison can run even faster than before, with the top running speed of 70 miles per hour. Their horns reduced in size as well, with the horn span of only 30cm due to the lack of usage. Now the Mini Bison only stand 1.5 meters tall, 2 meters long, with a higher set head and a longer tail. This animal inhabits all over North America and some parts of South America.
Scientific Classification
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Cetartiodactyla
Family
Bovidae
Genus
Bison
Species
Brevis
Habitat
The habitat that the Mini Bison live in is totally different from the one that American Bison lived in
Figure 2: Continental drift 250 million years after. Source from: http://rst.gsfc.nasa.gov/Sect2/PangeaUltima_scotese.jpg
. Although both of these bison range mostly in North America, but due to the effect of continental drift, the North America 250 million years ago is totally different compare to the one now. Most of the continents shifted towards the equator and joint together as a big continent. For example, Antarctic is now linked with Australia, Eurasia, Africa and America are all joint together as well. Sea level also rose when icebergs from Antarctica melted. The rest of the world is covered by the Pacific Ocean. The Mini Bison now inhabit mostly in North America and South America, as well as parts of Africa.
The climate in North America differs to the one 250 million years ago. The temperature generally becomes warmer as the continents shifts towards the equator. Due to global warming, the Mini Bison does not have to face harsh winters like they did before, since they are no more winter seasons on Earth anymore. However, the temperature in North America rose by 15 degrees Celsius, which relates back to why the Mini Bison had shed their fur.
Figure 3: Tropical North America 250 millions later. Source from: http://0.tqn.com/d/gohawaii/1/0/J/F/4/maui_tropical_plantation_001.jpg
The Mini Bison have a wider diet range than the American Bison. As North America becomes more tropical like, with taller trees and higher bushes, more animals inhabit there, providing a wider diet for the bison. Grass is not the only option for these bison now, they can also feed on insects and small mammals such as rabbits and rats. For the bison to catch their prey, it requires fast reaction and movement, that is why they developed longer legs and lighter body weight so it is easier for them to catch animals like rabbits and other insects.
Having a wider range of animal in North America also means more predators are introduced in the area. Classic predators such as Grey Wolves and Grizzly Bears are still threats to the bison. New predators such as leopards and cobras are now introduced in the area and can become a threat to the Mini Bison as well. Fortunately, none of those predators can catch up with the speed of the Mini Bison. If a Mini Bison is on the run, nothing can touch them. The only way the bison may be hunted down is when are eating. Wolves and bears usually ambush the bison while they are grazing the plains or eating off leafs from bushes.
Structural Adaptation 1. Longer legs - The Mini Bison evolved into developing longer legs in order to run faster and to become more agile. It is important for the Mini Bison to have longer legs when catching their prey, especially when facing animals like rats and rabbit, that can move really quickly in different directions. These animal prefer to eat other mammals than vegetation, since it provides higher energy and contains stronger flavor than vegetations. However, for the bison to successfully catch their prey, it requires them to be flexible and agile, and by developing longer legs can solve the problem, which then allows the bison to move faster and become more agile when catching their prey. The environmental pressure is the change of diet for the Mini Bison. In order to catch insects and mammals, having short but powerful legs were just not enough, therefore many American Bison died out during the continental drift when the food chain had changed. Only the ones that had slightly longer legs survived and past on their gene, in result of developing bison with long legs.
2. Development of canine and incisor teeth - Originally, bison only had molars to grind up t
Figure 4: Different types of Mini Bison's teeth. Source from: http://www.gtchild.co.uk/content/images/stories/teeth.jpg
he grass, but due to the diet change, Mini Bison now develop canines and incisors. Since the Mini Bison are omnivores, they feed on both plants and animals. This requires different types of teeth in order to chew up certain types of food. The development of canine teeth helps the bison to rip and tear the meat of rats and rabbits. These canine teeth are also useful for piercing and holding onto the prey. The incisors are broad and flat that are meant to cut and snip off pieces of food. They are useful for eating insects as they can snip them in pieces before swallowing to prevent them from wiggling down the throat. The environmental pressure of developing canines and incisors is the change of diet in the habitat. Since the Mini Bison are not herbivores anymore, without those types of teeth, they won't be able to chew on meat or insects and would only have grass as their main diet.
Behavioral Adaptation 1. Live separate from herd - Mini Bison does not live in herds like the American Bison did. Mainly because of the food source has been spread out into various areas. It is not possible for a herd of bison to chase after a single rat or rabbit, therefore they have to move separately. Historically, bison had lived in herds in order to protect themselves from predators, but due to the change of diet, each bison now has to seek for their own food separately. By traveling alone, it can help the animal to easily ambush their prey without having to alert them. But if the Mini Bison ambush their prey in herds, it can cause a large amount of noise and would certainly alert animals like the rabbits that has acute hearing. The environmental pressure of living away from a herd is the different type of diet. Since the Mini Bison feed on animals that have acute sense of hearing and smell, it forces the bison to live by itself so it is easier for them to catch their prey, to prevent alerting them and causing them to flee.
2. Protects cows (female bison) and calves - Adult Mini Bison would protect any cows and calves whenever they are in danger. When a new born bison or a cow is being chased by other predators, it yelps to signal nearby bison for help. Since bison also developed acute hearing, they are able to hear the signal even if they are kilometers away. When the adult bison sense the signal, they will run as fast as they can to protect which ever bison is in danger. The group of male bison would surround the cow or calf, forming a large circle to separate them away from the predator. No matter how big or how strong the predator is, it is still not a good idea for them to engage an attack when facing a large herd of roaring bison. By protecting the cows and calves, the bison can ensure that the new generation is safe and can pass on their genes to the next generation. The environmental pressure for the bison to develop such behavior is the increasing of predators and not living in herds anymore. Originally when the bison lived in herds, they were less concerned about being attacked by other predators. However, since the bison live separately now, it is more difficult to prevent predators from attacking, but in order to sustain and pass on their gene, they have no choice but to come to aid whenever a cow or a calf needs help.
Physiological Adaptation
1. Larger lungs for chasing and fleeing - Due to the fact that the Mini Bison have to always run, they developed lungs that can take in higher capacity of oxygen so that they can run longer distances. This is very useful for the Mini Bison to chase their prey, and also useful when it's chased by predators. When chasing prey like the rabbit, which moves quite fast as well, requires a lot of endurance when chasing after it. On the other hand, when the bison is chased by predators, it then also requires a lot of endurance to run away. The larger lungs are for both chasing, and fleeing. The environmental pressures for bison developing larger lungs are their diet and pressure from predators. For the bison to eat, they have to chase, when they are in danger, they have to flee. All these activities requires a excessive amount of running, therefore having lungs with bigger capacity can is certainly useful for the Mini Bison during every day of their life.
To Modern Bison, click here
To Fossil Bison, click here
The future animal, Bison Brevis, commonly known as the Mini Bison evolved from the American Bison 150 million years ago. The Latin name, Bison Brevis describes the size reduced compared to the American Bison. This Mini Bison is very different from the American Bison. The most significant difference is that the Mini Bison became omnivores; feeding on both vegetation and insects, as well as small mammals such as rabbits and rats. Their body size reduces from its previous sub species, but evolved into being more flexible and agile on land. This type of bison lost the shaggy fur due to the change of global climate, leaving only a thin layer of stubble below their neck and on their back. The Mini Bison also developed longer legs and reduced the body weight for better agility and reaction. Now the Mini Bison can run even faster than before, with the top running speed of 70 miles per hour. Their horns reduced in size as well, with the horn span of only 30cm due to the lack of usage. Now the Mini Bison only stand 1.5 meters tall, 2 meters long, with a higher set head and a longer tail. This animal inhabits all over North America and some parts of South America.
Scientific Classification
Habitat
The habitat that the Mini Bison live in is totally different from the one that American Bison lived in
The climate in North America differs to the one 250 million years ago. The temperature generally becomes warmer as the continents shifts towards the equator. Due to global warming, the Mini Bison does not have to face harsh winters like they did before, since they are no more winter seasons on Earth anymore. However, the temperature in North America rose by 15 degrees Celsius, which relates back to why the Mini Bison had shed their fur.
The Mini Bison have a wider diet range than the American Bison. As North America becomes more tropical like, with taller trees and higher bushes, more animals inhabit there, providing a wider diet for the bison. Grass is not the only option for these bison now, they can also feed on insects and small mammals such as rabbits and rats. For the bison to catch their prey, it requires fast reaction and movement, that is why they developed longer legs and lighter body weight so it is easier for them to catch animals like rabbits and other insects.
Having a wider range of animal in North America also means more predators are introduced in the area. Classic predators such as Grey Wolves and Grizzly Bears are still threats to the bison. New predators such as leopards and cobras are now introduced in the area and can become a threat to the Mini Bison as well. Fortunately, none of those predators can catch up with the speed of the Mini Bison. If a Mini Bison is on the run, nothing can touch them. The only way the bison may be hunted down is when are eating. Wolves and bears usually ambush the bison while they are grazing the plains or eating off leafs from bushes.
Structural Adaptation
1. Longer legs - The Mini Bison evolved into developing longer legs in order to run faster and to become more agile. It is important for the Mini Bison to have longer legs when catching their prey, especially when facing animals like rats and rabbit, that can move really quickly in different directions. These animal prefer to eat other mammals than vegetation, since it provides higher energy and contains stronger flavor than vegetations. However, for the bison to successfully catch their prey, it requires them to be flexible and agile, and by developing longer legs can solve the problem, which then allows the bison to move faster and become more agile when catching their prey. The environmental pressure is the change of diet for the Mini Bison. In order to catch insects and mammals, having short but powerful legs were just not enough, therefore many American Bison died out during the continental drift when the food chain had changed. Only the ones that had slightly longer legs survived and past on their gene, in result of developing bison with long legs.
2. Development of canine and incisor teeth - Originally, bison only had molars to grind up t
Behavioral Adaptation
1. Live separate from herd - Mini Bison does not live in herds like the American Bison did. Mainly because of the food source has been spread out into various areas. It is not possible for a herd of bison to chase after a single rat or rabbit, therefore they have to move separately. Historically, bison had lived in herds in order to protect themselves from predators, but due to the change of diet, each bison now has to seek for their own food separately. By traveling alone, it can help the animal to easily ambush their prey without having to alert them. But if the Mini Bison ambush their prey in herds, it can cause a large amount of noise and would certainly alert animals like the rabbits that has acute hearing. The environmental pressure of living away from a herd is the different type of diet. Since the Mini Bison feed on animals that have acute sense of hearing and smell, it forces the bison to live by itself so it is easier for them to catch their prey, to prevent alerting them and causing them to flee.
2. Protects cows (female bison) and calves - Adult Mini Bison would protect any cows and calves whenever they are in danger. When a new born bison or a cow is being chased by other predators, it yelps to signal nearby bison for help. Since bison also developed acute hearing, they are able to hear the signal even if they are kilometers away. When the adult bison sense the signal, they will run as fast as they can to protect which ever bison is in danger. The group of male bison would surround the cow or calf, forming a large circle to separate them away from the predator. No matter how big or how strong the predator is, it is still not a good idea for them to engage an attack when facing a large herd of roaring bison. By protecting the cows and calves, the bison can ensure that the new generation is safe and can pass on their genes to the next generation. The environmental pressure for the bison to develop such behavior is the increasing of predators and not living in herds anymore. Originally when the bison lived in herds, they were less concerned about being attacked by other predators. However, since the bison live separately now, it is more difficult to prevent predators from attacking, but in order to sustain and pass on their gene, they have no choice but to come to aid whenever a cow or a calf needs help.
Physiological Adaptation
1. Larger lungs for chasing and fleeing - Due to the fact that the Mini Bison have to always run, they developed lungs that can take in higher capacity of oxygen so that they can run longer distances. This is very useful for the Mini Bison to chase their prey, and also useful when it's chased by predators. When chasing prey like the rabbit, which moves quite fast as well, requires a lot of endurance when chasing after it. On the other hand, when the bison is chased by predators, it then also requires a lot of endurance to run away. The larger lungs are for both chasing, and fleeing. The environmental pressures for bison developing larger lungs are their diet and pressure from predators. For the bison to eat, they have to chase, when they are in danger, they have to flee. All these activities requires a excessive amount of running, therefore having lungs with bigger capacity can is certainly useful for the Mini Bison during every day of their life.
Bibliography
1. Babylon. (2010). Latin-Dictionary. Retrieved July 30th, 2010, from http://www.babylon.com/define/112/Latin-Dictionary.html
2. History of the Universe. (N/A). TimeLine. Retrieved July 30th, 2010, from http://www.historyoftheuniverse.com/tl1.html
3. NCSU Soil Science. (1999). Tropical Environment. Retrieved July 30th, 2010, from http://www.soil.ncsu.edu/lockers/Smyth_J/TropEnv/TROPENV.HTM
4. Simplesteps. (2010). Types of Teeth. Retrieved July 30th, 2010, from http://www.simplestepsdental.com/SS/ihtSS/r.WSIHW/st.31843/t.31885/pr.3.html
5. Wikipedia. (2010). Lung volumes. Retrieved July 30th, 2010, from http://en.wikipedia.org/wiki/Lung_volumes